The fifth yama is Aparigraha (ah-paari-gra-ha). Parigraha means possessiveness or covetousness. The adding of an ‘a’ to a Sanskrit words usually denotes the opposite. Thus the fifth yama or restraint means freedom from possessiveness or hoarding; not desiring more than what we need. On a subtler note, it is more about attachment. You can free yourself from attachment to material things, but can you do the same emotionally. Someone trying to control another is an example of unwanted emotional attachment.
Aparigraha also denotes freedom from greed. When you see a person with enormous wealth, it may not be an example of greed. But a person wanting to live a lifestyle beyond one’s means is a great example. If you have growing children, it is important to take some time to explain to them what is greed and what is not.
[From a May 2006 newsletter Evolution article that I wrote]